It is well known that voicemail systems increase the convenience of using telephones by recording messages when a user cannot take a call, in such instances where the user is, for example, unavailable and misses the call, already on the phone, otherwise unavailable, etc. For mobile devices, voicemail is also advantageous when the mobile device is turned-off or out of its coverage area. With the increasing popularity of mobile devices, particularly those with, for example, call waiting features, voicemail systems have become popular among a wide cross-section of consumers.
A popular feature for voicemail users, especially those with mobile phones, is notification of a received message. Typically, an automatically generated notification message will be sent from a wireless carrier to a user's mobile device to alert the user that a voicemail message has been received and is waiting for pickup. The notification message often is sent via Short Message Service (SMS). A typical notification message might include information about the call, such as, for example, the name and/or number of the caller, the time the call was received, the length of the message, etc. A notification message may also include a unique identifier that tells the wireless carrier's voicemail system which message to play. Users generally dial in to voicemail systems through wireless networks to retrieve and listen to their messages.
However, the process of dialing into a voicemail system through a wireless network and waiting for the voicemail system to retrieve the relevant message from a voice mailbox is often slow. Thus, to reduce this delay, further improvements have been made to voicemail systems, including preparation of voicemail messages for playback when the voicemail system anticipates that a user is about to dial in to listen to a stored message. Specifically, when the notification that a voicemail message has been received is sent to the mobile device, for example, the mobile device can, in turn, notify the voicemail system that the user is about to dial in to the system to play the message identified by a unique identifier attached to the notification message. Sending the message in advance over a separate data connection allows the voicemail system to queue up the message for playback so that the message can be played as soon as the mobile device establishes a voice connection to the voicemail system.
However, this approach may have several drawbacks. For example, a fast, reliable connection may not be available at a given time because, for example, there may not be data coverage in a given location, thus preventing the delivery of notification messages to the mobile device, and/or notification messages to the voicemail system. Because typical notification messages are sent using Short Message Service (SMS), even if an SMS message is successfully sent, SMS messages usually travel slowly under normal conditions. Furthermore, SMS is inherently unreliable because SMS messages may not be acknowledged and delivery is not guaranteed. Thus, further problems are likely, as it is possible that, for example, the wrong message may be played, the voicemail system may not be ready (also causing delays), the voicemail system may be non-responsive, or the like.
Therefore, there is a need to overcome these and other disadvantages caused by the inherent unreliability of SMS messaging alone to provide advance notification to voicemail systems. A user could then receive notice of a received voicemail message and then enjoy fast, reliable playback of that message.